1. Field of Invention
This invention relates to fuel systems for internal combustion engines and more particularly to means for reducing the amount of evaporated fuel gas which enters the atmosphere.
2. Prior Art
According to conventional type apparauses for treating evaporated fuel gas, evaporated gases from a gas tank or float chamber of a carburetor are absorbed into a charcoal canister containing activated charcoal or the like. The gas vapors are then drawn out of the canister into the intake system of the engine by means of the negative pressure in a carburetor or an intake manifold of the engine. However, these prior art apparatuses include no means for adjusting the air/fuel ratio of the gas mixture provided to the engine. Therefore, there is a major shortcoming in that the fuel/air ratio becomes too rich under conditions when the temperature of the fuel is high and more fuel vapor exists than usual. As a result thereof, the condition of the exhaust, the gas mileage and the running efficiency of the motor vehicle deteriorates.